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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/video/backlight/ep93xx_bl.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/video/backlight/ep93xx_bl.c')
-rw-r--r-- | drivers/video/backlight/ep93xx_bl.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/video/backlight/ep93xx_bl.c b/drivers/video/backlight/ep93xx_bl.c new file mode 100644 index 0000000000..2387009d45 --- /dev/null +++ b/drivers/video/backlight/ep93xx_bl.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for the Cirrus EP93xx lcd backlight + * + * Copyright (c) 2010 H Hartley Sweeten <hsweeten@visionengravers.com> + * + * This driver controls the pulse width modulated brightness control output, + * BRIGHT, on the Cirrus EP9307, EP9312, and EP9315 processors. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/fb.h> +#include <linux/backlight.h> + +#define EP93XX_MAX_COUNT 255 +#define EP93XX_MAX_BRIGHT 255 +#define EP93XX_DEF_BRIGHT 128 + +struct ep93xxbl { + void __iomem *mmio; + int brightness; +}; + +static int ep93xxbl_set(struct backlight_device *bl, int brightness) +{ + struct ep93xxbl *ep93xxbl = bl_get_data(bl); + + writel((brightness << 8) | EP93XX_MAX_COUNT, ep93xxbl->mmio); + + ep93xxbl->brightness = brightness; + + return 0; +} + +static int ep93xxbl_update_status(struct backlight_device *bl) +{ + return ep93xxbl_set(bl, backlight_get_brightness(bl)); +} + +static int ep93xxbl_get_brightness(struct backlight_device *bl) +{ + struct ep93xxbl *ep93xxbl = bl_get_data(bl); + + return ep93xxbl->brightness; +} + +static const struct backlight_ops ep93xxbl_ops = { + .update_status = ep93xxbl_update_status, + .get_brightness = ep93xxbl_get_brightness, +}; + +static int ep93xxbl_probe(struct platform_device *dev) +{ + struct ep93xxbl *ep93xxbl; + struct backlight_device *bl; + struct backlight_properties props; + struct resource *res; + + ep93xxbl = devm_kzalloc(&dev->dev, sizeof(*ep93xxbl), GFP_KERNEL); + if (!ep93xxbl) + return -ENOMEM; + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) + return -ENXIO; + + /* + * FIXME - We don't do a request_mem_region here because we are + * sharing the register space with the framebuffer driver (see + * drivers/video/ep93xx-fb.c) and doing so will cause the second + * loaded driver to return -EBUSY. + * + * NOTE: No locking is required; the framebuffer does not touch + * this register. + */ + ep93xxbl->mmio = devm_ioremap(&dev->dev, res->start, + resource_size(res)); + if (!ep93xxbl->mmio) + return -ENXIO; + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.max_brightness = EP93XX_MAX_BRIGHT; + bl = devm_backlight_device_register(&dev->dev, dev->name, &dev->dev, + ep93xxbl, &ep93xxbl_ops, &props); + if (IS_ERR(bl)) + return PTR_ERR(bl); + + bl->props.brightness = EP93XX_DEF_BRIGHT; + + platform_set_drvdata(dev, bl); + + ep93xxbl_update_status(bl); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int ep93xxbl_suspend(struct device *dev) +{ + struct backlight_device *bl = dev_get_drvdata(dev); + + return ep93xxbl_set(bl, 0); +} + +static int ep93xxbl_resume(struct device *dev) +{ + struct backlight_device *bl = dev_get_drvdata(dev); + + backlight_update_status(bl); + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(ep93xxbl_pm_ops, ep93xxbl_suspend, ep93xxbl_resume); + +static struct platform_driver ep93xxbl_driver = { + .driver = { + .name = "ep93xx-bl", + .pm = &ep93xxbl_pm_ops, + }, + .probe = ep93xxbl_probe, +}; + +module_platform_driver(ep93xxbl_driver); + +MODULE_DESCRIPTION("EP93xx Backlight Driver"); +MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ep93xx-bl"); |